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Plug-in hybrid electric vehicles emit almost 5x greater global warming emissions than lab-reported figures show, as per a recent analysis.

Growing Discrepancy In Official and Real-World CO2 Output

Statistics reveals that PHEVs release only 19% less CO₂ than traditional petrol and diesel cars, based on analysis conducted by a non-profit organization. That contrasts significantly with lab tests, which assumed a 75% reduction in pollution.

Analysts studied information from onboard fuel consumption meters of eight hundred thousand vehicles sold in the EU between 2021 and 2023. The team found that actual CO₂ output from PHEVs in 2023 were 4.9 times higher than official estimates, increased from three and a half times in 2021.

“Actual CO2 output are increasing, while lab-reported figures are decreasing,” stated a lead analyst participating in the study. “This discrepancy is widening and creates a significant problem. Consequently, PHEVs emit almost as much as gasoline cars.”

Primary Factors Behind the Emissions Gap

Researchers linked most of the difference to overestimates of the “electric driving share” – the percentage of kilometers driven in electric power relative to overall mileage. They found that only 27% of driving was done in electric mode, while official estimates suggested over four-fifths.

Additionally, when operating in electric mode, emission levels were well above lab estimates. That occurred because EV motors were not strong sufficient to function alone, resulting to engines burning fossil fuels for nearly a third of the distance covered in EV mode.

Policy and Economic Implications

According to estimates, the underestimation of PHEV CO2 output enabled four large carmaker companies to escape more than €5bn in fines from 2021 and 2023, by artificially simplifying adherence with EU fleet-average CO₂ standards.

Additionally, drivers of PHEVs could spend approximately €500 more annually in operating expenses than is estimated under laboratory tests.

“The bold statements that automakers like to make about their PHEV vehicles are clearly far from the mark,” commented a automotive analyst. “Buyers are being duped into believing that by purchasing a PHEV, they are helping the environment and saving costs. In reality, PHEVs are little improved than standard petrol and diesel cars in terms of fuel use, CO₂ production, and operating expenses.”

Political Discussion and Automotive Pressure

Hybrid cars have recently been brought back into policy debates as carmakers have lobbied the European Union to weaken CO₂ standards. A planned prohibition on sales of new combustion engine cars in 2035 has faced intense lobbying from the car sector and resistance from EU countries with large automotive industries.

Some senior politicians have suggested plug-in hybrids as a potential “compromise” solution to introduce in the regulation.

An external energy policy specialist, who was not involved with the study, described the report a “very useful addition” after years in which parts of the car industry claimed there was insufficient information to properly evaluate actual CO2 output.

“The results show, beyond any doubt, that the difference between official and actual PHEV energy use and CO₂ output is much, much larger than for gasoline or conventional cars,” they stated. “All regulatory changes regarding PHEVs should be implemented with utmost care and in the light of this data.”